Subframe assembly for a vehicle

ABSTRACT

A subframe assembly for a vehicle, including: a straight arm; and a side bracket including a base coupled to an outboard side of the straight arm; wherein the outboard side of the straight arm defines a recess; and wherein an inboard side of the base of the side bracket includes a protrusion that nests conformally within the recess defined by the outboard side of the straight arm. Top and bottom edges of the outboard side of the straight arm, the recess, the inboard side of the base of the side bracket, and the protrusion are chamfered. The chamfered portions of the top and bottom edges of the outboard side of the straight arm, the recess, the inboard side of the base of the side bracket, and the protrusion are welded to join the side bracket to the outboard side of the straight arm.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present disclosure is a continuation-in-part (CIP) of co-pendingU.S. patent application Ser. No. 17/568,008, filed on Jan. 4, 2022, andentitled “SUBFRAME ASSEMBLY FOR A VEHICLE,” which is a continuation(CON) of U.S. Pat. No. 11,247,726, issued on Feb. 15, 2022, and entitled“SUBFRAME ASSEMBLY FOR A VEHICLE,” the contents of both of which areincorporated in full by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to the automotive field, andspecifically the internal combustion engine (ICE) vehicle,hybrid-electric vehicle (HEV), and electric vehicle (EV) fields. Moreparticularly, the present disclosure relates to a subframe assembly(e.g., a front subframe assembly) for a vehicle that includes a strong,rigid connection between a crossmember, a straight arm, and a sidebracket in the area of a control arm connection for a wheel suspension.

BACKGROUND

In some conventional and novel ICE vehicle, HEV, and EV designs, theengine or motor is coupled to a front (or rear) subframe assembly thatmay be partially or wholly extruded for weight and costs savings, aswell as structural strength and overall vehicle integrity in the eventof a crash. Extruded aluminum, for example, provides many advantagesover steel box and/or cast constructions. This subframe assemblytypically consists of a frame-like structure that includes at least oneextruded crossmember (and likely a pair of extruded crossmembers)disposed between a pair of elongate extruded arm members. The engine ormotor is coupled to the subframe assembly via a plurality of mounts(i.e., engine mounts or motor mounts).

In different crash load cases, the subframe assembly can receive hugeamounts of energy. Ideally, the subframe assembly itself absorbs asignificant amount of that energy (and transfers what is left to thebattery frame in the rear part of the subframe, for example), achieves alow vehicle pulse index (i.e., g-forces), and has little to no intrusioninto the occupant compartment of the vehicle.

Some vehicle subframes are casted, and thus undesirably brittle in acrash, and are thus designed to detach from the vehicle in the event ofa crash. In such cases, the brittle structure does not absorb muchenergy, and upon detachment, such as at the connection between acrossmember, a straight arm, and an attachment bracket for a control armconnection of the wheel assembly, no further energy is absorbed by thesubframe assembly. Some subframe assemblies including a connectionbetween a crossmember, a straight arm, and an attachment bracket arerather configured to collapse in a crash. When a subframe assemblycollapses, the subframe assembly does not absorb very much energy.Similarly, some subframe assemblies have the attachment bracketpositioned between the crossmember and the straight arm, which shortensthe straight arm and results in extra welds that serve as weak pointsduring a crash and can affect the ductility of the straight arm. Theshorter straight arms absorb less energy and the subframe assemblycollapses at the welds, resulting in very little energy being absorbedby the subframe. While the subframe assembly can be strengthened inthese scenarios by connecting the subframe assembly to the vehicle body,such as by screws, these connections can result in increased noise,vibration, and ride harshness for the vehicle occupants.

The above-described background relating to the various connectionsbetween members of a subframe assembly is merely intended to provide acontextual overview of some current issues and is not intended to beexhaustive. Other contextual information may become apparent to those ofordinary skill in the art upon review of the following description ofexemplary embodiments.

SUMMARY

The present disclosure generally provides a subframe assembly with astrong, rigid connection between a crossmember, a straight arm, and aside bracket in an area of a control arm connection for a wheelsuspension. In particular, the side bracket is metallurgically bonded toa side of the straight arm (at or close to an end of the straight arm),and both the side bracket and the straight arm are received into andmetallurgically bonded to an end bracket of the crossmember, with theend bracket being positioned at an end of the crossmember. The use ofthis strong, rigid connection between the various components providesfor the desired rigidity, ductility, and strength of the connection andits components, and in particular, the length, rigidity, and ultimatedeformability of the straight arm, for a desired crashworthiness of thesubframe assembly.

In one exemplary embodiment, the present disclosure provides a subframeassembly for a vehicle that includes a crossmember, a straight arm, anda side bracket. The crossmember includes an end bracket disposed at anend thereof. The straight arm is received into and metallurgicallybonded to the end bracket of the crossmember. The side bracket includesa base and a rear bracket arm. The base is metallurgically bonded to aside of the straight arm adjacent to the end of the crossmember. Therear bracket arm extends from an end of the base and defines a holeadapted to receive a screw or pin for connecting a control arm of awheel suspension to the subframe assembly. The rear bracket arm is atleast partially received into and metallurgically bonded to the endbracket of the crossmember.

In one exemplary embodiment of the subframe assembly, a portion of therear bracket arm protrudes from the end bracket of the crossmember andmetallurgical bonds are formed at interfaces between the end bracket ofthe crossmember and protruding surfaces of the rear bracket arm. Inanother exemplary embodiment of the subframe assembly, the rear bracketarm includes an arm portion extending from and disposed orthogonal tothe base and a body portion extending from the arm portion, the bodyportion extending beyond an end of the base, being offset from the base,and defining the hole. Optionally, the body portion defines a wedgeshape with a truncated thin edge distal to the arm portion, thetruncated thin edge being disposed proximal to a back portion of thecrossmember. Optionally, the truncated thin edge defines an end surfaceof the rear bracket arm, and the end surface and top and bottom basesurfaces of the wedge shape protrude from the end bracket of thecrossmember. Optionally, metallurgical bonds are formed on protrudedportions of each of the end surface, the top base surface, and thebottom base surface at edges of the end bracket of the crossmember thatjoin the side bracket to the crossmember. Optionally, metallurgicalbonds are also formed on side surfaces of the arm portion and the baseat the edges of the end bracket of the crossmember that also join theside bracket to the crossmember. In a further exemplary embodiment ofthe subframe assembly, the straight arm defines a depression at an uppersurface thereof adjacent to the side surface, and the depression isoffset from the side bracket such that the depression does not overlapwith the side bracket along a length of the straight arm. In a stillfurther exemplary embodiment of the subframe assembly, the base isoffset from the end of the straight arm.

In another exemplary embodiment, the present disclosure provides a sidebracket adapted to connect a control arm of a wheel suspension to asubframe assembly for a vehicle. The side bracket includes a base, amiddle bracket arm, and a rear bracket arm. The base is adapted to bemetallurgically bonded to a side of a straight arm of the subframeassembly adjacent to an end of the straight arm. The middle bracket armextends from and is disposed orthogonal to the base between ends of thebase. The middle bracket arm defines a clearance hole adapted to receivea screw or pin adapted to connect the control arm to the subframeassembly. The rear bracket arm includes an arm portion and a bodyportion. The arm portion extends from and is disposed orthogonal to thebase. The body portion extends from the arm portion. The body portionextends beyond one of the ends of the base, is offset from the base, anddefines a hole adapted to receive the screw or pin. The body portion isadapted to be at least partially received into and metallurgicallybonded to an end bracket of a crossmember of the subframe assembly. Theend bracket is disposed at an end of the crossmember.

In one exemplary embodiment of the side bracket, the body portiondefines a wedge shape with a truncated thin edge distal to the armportion, the truncated thin edge defining an end surface adapted to bedisposed proximal to a back portion of the crossmember. Optionally, theend surface and top and bottom base surfaces of the wedge shape areadapted to protrude from the end bracket of the crossmember. Optionally,the body portion defines an inner surface facing the middle bracket thatdefines an opening to the hole, and the body portion tapers from theinner surface to the end surface. Optionally, the body portion definesan angled surface distal to the arm portion that extends between the endsurface and the inner surface, and an offset surface disposed proximalto the arm portion that extends parallel to and offset from a bottomsurface of the base, the angled surface and the offset surface formingan acute angle.

In a further exemplary embodiment, the present disclosure provides amethod for manufacturing a subframe assembly for a vehicle. The methodincludes metallurgically bonding a base of a side bracket to a sidesurface of a straight arm, wherein the side bracket includes the baseand a rear bracket arm extending from an end of the base and defining ahole adapted to receive a screw or pin for connecting a control arm of awheel suspension to the subframe assembly. The method also includesinserting an end of the straight arm and at least a portion of the rearbracket arm into an end bracket of a crossmember, wherein the endbracket is disposed at an end of the crossmember. The method furtherincludes metallurgically bonding each of the end of the straight arm andthe rear bracket arm to the end bracket of the crossmember.

In one exemplary embodiment of the method, the method further includesinserting an end of the base into the end bracket and metallurgicallybonding the end of the base to the end bracket of the crossmember. Inanother exemplary embodiment of the method, a portion of the rearbracket arm protrudes from the end bracket of the crossmember, andmetallurgically bonding the rear bracket arm to the end bracket of thecrossmember includes forming metallurgical bonds at interfaces betweenthe end bracket of the crossmember and protruding surfaces of the rearbracket arm. In a further exemplary embodiment of the method, the rearbracket arm includes an arm portion extending from and disposedorthogonal to the base and a body portion extending from the armportion, the body portion extending beyond an end of the base, beingoffset from the base, and defining the hole, and inserting the end ofthe straight arm and the at least the portion of the rear bracket arminto the end bracket of the crossmember includes positioning the end ofthe straight arm and an end of the body portion proximal to a backportion of the crossmember. In a still further exemplary embodiment ofthe method, metallurgically bonding the base of the side bracket to theside surface of the straight arm includes locating the side bracket suchthat the base is offset from the end of the straight arm. In still afurther exemplary embodiment of the method, the straight arm defines adepression at an upper surface thereof adjacent to the side surface, andmetallurgically bonding the base of the side bracket to the side surfaceincludes locating the side bracket such that the side bracket does notoverlap with the depression along a length of the straight arm.

In another exemplary embodiment, the present disclosure provides asubframe assembly for a vehicle, the subframe assembly including: astraight arm; and a side bracket including a base coupled to an outboardside of the straight arm; wherein the outboard side of the straight armdefines a recess; and wherein an inboard side of the base of the sidebracket includes a protrusion that nests conformally within the recessdefined by the outboard side of the straight arm. Top and bottom edgesof the outboard side of the straight arm, the recess, the inboard sideof the base of the side bracket, and the protrusion are chamfered. Thechamfered portions of the top and bottom edges of the outboard side ofthe straight arm, the recess, the inboard side of the base of the sidebracket, and the protrusion are welded to join the side bracket to theoutboard side of the straight arm. Optionally, the protrusion is asquare or rectangular protrusion having radiused corners. Optionally,the protrusion is a hollow structure. The straight arm is an extrudedstructure. The side bracket is adapted to receive a suspension componentof the vehicle.

In a further exemplary embodiment, the present disclosure provides aside bracket for a subframe assembly for a vehicle, the side bracketincluding: a base adapted to be coupled to an outboard side of astraight arm; wherein an inboard side of the base includes a protrusionthat is adapted to nest conformally within a recess defined by theoutboard side of a straight arm. Top and bottom edges of the inboardside of the base and the protrusion are chamfered. The chamferedportions of the inboard side of the base and the protrusion are adaptedto be welded to join the side bracket to the outboard side of thestraight arm. Optionally, the protrusion is a square or rectangularprotrusion having radiused corners. Optionally, the protrusion is ahollow structure. The straight arm is an extruded structure. The sidebracket is adapted to receive a suspension component of the vehicle.

In a still further exemplary embodiment, the present disclosure providesa straight arm for a subframe assembly for a vehicle, the straight armincluding: an extruded structure having an outboard side adapted to becoupled to a side bracket; wherein the outboard side of the extrudedstructure defines a recess; and wherein the recess is adapted toconformally receive a protrusion of an inboard side of a base of theside bracket. Top and bottom edges of the outboard side of the straightarm and the recess are chamfered. The chamfered portions of the top andbottom edges of the outboard side of the straight arm and the recess areadapted to be welded to join the side bracket to the outboard side ofthe straight arm. Optionally, the protrusion is a square or rectangularprotrusion having radiused corners. Optionally, the protrusion is ahollow structure. The side bracket is adapted to receive a suspensioncomponent of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated and described herein withreference to the various drawings, in which like reference numbers areused to denote like system components/method steps, as appropriate, andin which:

FIG. 1 is a perspective view of one exemplary embodiment of the (front)subframe assembly of the present disclosure;

FIG. 2 is a partial perspective view of the subframe assembly of FIG. 1at a connection between the (rear) crossmember, a straight arm, and aside bracket with a lower control arm of the wheel suspension connectedthereto;

FIG. 3 is an exploded partial perspective view of the subframe assemblyof FIG. 1 at the connection shown in FIG. 2 with the lower control armof the wheel suspension;

FIG. 4 is a side perspective view of the side bracket of FIGS. 1-3 ;

FIG. 5 is a partial perspective view of the subframe assembly of FIG. 1at the connection shown in FIG. 2 , illustrating locations ofmetallurgical bonds between members of the connection;

FIG. 6 is an alternative view of the partial perspective view of FIG. 5illustrating locations of the metallurgical bonds between members of theconnection;

FIG. 7 is a flowchart of a method for manufacturing a subframe assemblyfor a vehicle;

FIG. 8 is a side perspective view of the subframe assembly of FIG. 1deformed from absorbing energy during a crash event;

FIG. 9 is a partial perspective view of the subframe assembly at aconnection between the (rear) crossmember, a straight arm, and a sidebracket, highlighting the associated weld joints;

FIG. 10 is a perspective view of another exemplary embodiment of the(front) subframe assembly of the present disclosure, utilizing a sidebracket with a base including an inboard side protrusion and a straightarm with a corresponding recess, as well as conformal chamfered weldjoints;

FIG. 11 is a partial perspective view of the straight arm andcorresponding recess of FIG. 10 ;

FIG. 12 is a perspective view of the side bracket with the baseincluding the inboard side protrusion of FIG. 10 ; and

FIG. 13 is a partial perspective view of the side bracket with the baseincluding the inboard side protrusion, the straight arm with thecorresponding recess, and the conformal chamfered weld joints of FIG. 10.

DETAILED DESCRIPTION OF EMBODIMENTS

Again, the present disclosure generally provides a subframe assemblywith a strong, rigid connection between a crossmember, a straight arm,and a side bracket in an area of a control arm connection for a wheelsuspension. In particular, the side bracket is metallurgically bonded tothe straight arm (at or close to an end of the straight arm), and boththe side bracket and the straight arm are received into andmetallurgically bonded to an end bracket of the crossmember with the endbracket being positioned at an end of the crossmember. The crossmember,the straight arm, and the side bracket can each be extruded aluminum,for example, having high-ductility and high-strength materialproperties.

The use of this strong, rigid connection provides for the desiredrigidity, ductility, and strength of the connection and its componentsfor a desired crashworthiness of the subframe assembly. In a crashevent, the subframe assembly can deform, such as by bending into aU-shape, without detaching from the vehicle, while avoiding stack-upwith other parts of the vehicle. In particular, the straight arm canbend in a designed location without interference from the side bracketto facilitate the desired deformation of the subframe assembly.

FIG. 1 is a perspective view of one exemplary embodiment of the (front)subframe assembly 10 of the present disclosure. Referring to FIG. 1 , inone exemplary embodiment, the subframe assembly 10 of the presentdisclosure includes a front crossmember 20, a rear crossmember 30,straight arms 50, and side arm brackets 100. Each of the frontcrossmember 20, the rear crossmember 30, the straight arms 50, and theside arm brackets 100 can include an extruded metal structure, such asan aluminum structure, having high-ductility and high-strength materialproperties. In some embodiments, at least the straight arms 50 arerectangular extruded structures. The use of extruded metal structurescan provide a desired ductility and strength in the event of a crash,while keeping weight of the subframe assembly 10 to a minimum.

By way of example, the front crossmember 20, the rear crossmember 30,and the straight arms 50 may form a generally rectangular framestructure, which may include other spanning members that provide theframe structure with structural integrity and stability. This structuralintegrity and stability can further be established at the connections15. At each connection 15, and as will be discussed in greater detailbelow, the rear crossmember 30, a straight arm 50, and a side bracket100 are all metallurgically bonded to one another to form a strong,rigid connection.

FIG. 2 is a partial perspective view of the subframe assembly 10 of FIG.1 at the connection 15 between the rear crossmember 30, the straight arm50, and the side bracket 100 with a lower control arm 200 of the wheelsuspension connected thereto. FIG. 3 is an exploded partial perspectiveview of the subframe assembly 10 of FIG. 1 at the connection 15 shown inFIG. 2 with the lower control arm 200 of the wheel suspension. FIG. 4 isa side perspective view of the side bracket 100 of FIGS. 1-3 . Referringto FIGS. 2 and 3 , the rear crossmember 30 includes an end bracket 34disposed at an end thereof. The rear crossmember 30 includes a backportion 32 extending a length of the rear crossmember 30, and an upperbracket arm 36 and a lower bracket arm 38, each extending from the endof the back portion 32 on opposite sides of the back portion 32. Theback portion 32, the upper bracket arm 36, and the lower bracket arm 38combine to form a U-shaped end bracket 34. While only one U-shaped endbracket 34 is described, a second U-shaped end bracket 34 can be locatedat an opposite end of the rear crossmember 30, as can be seen in FIG. 1.

The straight arm 50 can define a depression 52 at an upper surfacethereof adjacent to the side surface of the straight arm 50. Thedepression 52 can be a slot extending across and transverse to a lengthof the straight arm 50. An end of the straight arm is received into andmetallurgically bonded to the end bracket 34 of the rear crossmember 30.

The side bracket 100 includes a base 110, a middle bracket arm 120, anda rear bracket arm 130. The base 110 is metallurgically bonded to theside of the straight arm 50 adjacent to the end of the rear crossmember30, and in particular, to the side located on an outer side of thesubframe assembly 10. As can be seen in FIG. 1 , the base 110 ismetallurgically bonded to the side of the straight arm 50 in a positionso that the depression 52 of the straight arm 50 is offset from the sidebracket 100 such that the depression 52 does not overlap with the sidebracket 100 along a length of the straight arm 50. The base 110 can alsobe offset from an end of the straight arm 50.

Referring to FIG. 4 , the middle bracket arm 120 extends from and isdisposed orthogonal to the base 110 between ends 114 of the base. Themiddle bracket arm 120 defines a clearance hole adapted to receive acontrol arm fastener 210, such as a screw or pin. As can be seen inFIGS. 2 and 3 , the control arm fastener 210 is adapted to connect thecontrol arm 200 of the wheel suspension, at a control arm bushing 205,to the subframe assembly 10.

The rear bracket arm 130 extends from an end 114 of the base and definesa hole 136 adapted to receive the control arm fastener 210. As can beseen in FIGS. 2 and 3 , the rear bracket arm 130 is at least partiallyreceived into and metallurgically bonded to the end bracket 34 of therear crossmember 40.

The rear bracket arm 130 includes an arm portion 132 and a body portion134. The arm portion 132 can extend from and be disposed orthogonal tothe base 110. The body portion 134 can extend from the arm portion 132.The body portion 134 can extend beyond one of the ends 114 of the base110 and can be offset from the base 110. Here, the body portion 134defines the hole 136. As can be seen in FIGS. 2 and 3 , the body portion134 is adapted to be at least partially received into andmetallurgically bonded to the end bracket 34 of the rear crossmember 40.

The body portion 134 defines a wedge shape with a truncated thin edgedistal to the arm portion 132. The truncated thin edge can define an endsurface 138. The end surface 138 can be disposed proximal to the backportion 32 of the rear crossmember 40. As the base 110 can be offsetfrom an end of the straight arm 50, the base 110 can be positioned suchthat the end surface 138 aligns with the end of the straight arm 50.

The wedge shape of the body portion 134 also defines base surfaces (topand bottom) 140, an inner surface 142, an offset surface 144, and anangled surface 146. As can be seen in FIG. 2 , the end surface 138, andthe base surfaces 140 of the wedge shape can protrude from the endbracket 34 of the rear crossmember 40.

The inner surface 142 faces the middle bracket 120 and defines anopening to the hole 136. The body portion 134 can taper from the innersurface 142 to the end surface 138. The angled surface 146 can be distalto the arm portion 132 and can extend between the end surface 138 andthe inner surface 142. The offset surface 144 can be disposed proximalto the arm portion 132 and can extend parallel to and offset from abottom surface 112 of the base 110. The angled surface 146 and theoffset surface 144 can form an acute angle.

As disclosed above, the connection 15 is formed by metallurgicallybonding the side bracket 110 to a side of the straight arm 50, andmetallurgically bonding both the side bracket 110 and the straight arm50 to the rear crossmember 30. Each of the metallurgical bonds can be aweld or other bond with the desired strengths and properties.

FIG. 5 is a partial perspective view of the subframe assembly 10 of FIG.1 at the connection 15 shown in FIG. 2 , illustrating locations ofmetallurgical bonds 16, 17, 18 between members of the connection 15.FIG. 6 is an alternative view of the partial perspective view of FIG. 5, illustrating locations of the metallurgical bonds 16, 17, 18 betweenmembers of the connection 15. Referring to FIGS. 5 and 6 , metallurgicalbonds 16 join the side bracket 110 to the straight arm 50, metallurgicalbonds 17 join the side bracket 110 to the rear crossmember 30, andmetallurgical bonds 18 join the straight arm 50 to the rear crossmember40. In FIGS. 5 and 6 , some of the metallurgical bonds 16, 17, and 18are behind the structures shown, but are still illustrated forinformational purposes. The metallurgical bonds 16, 17, and 18 can becontinuous bonds, separate bonds, and a combination thereof.

In particular, the metallurgical bonds 16 can be formed along the sidesof the base 110 and along the end 114 of the base 110 opposite the rearbracket arm 120 adjacent to the bottom surface 112 of the base 110. Themetallurgical bonds 16 can join the sides of the base 110 and the end114 to the side surface of the straight arm 50.

A portion of the rear bracket arm 130 can protrude from the end bracket34 of the rear crossmember 30 and the metallurgical bonds 17 can beformed at interfaces between the end bracket 34 of the rear crossmember30 and protruding surfaces of the rear bracket arm 130. In particular,the metallurgical bonds 17 can be formed on protruding portions of eachof the end surface 138, the top and bottom base surfaces 140 at edges ofthe end bracket 34 of the rear crossmember 30 to join the side bracket100 to the rear crossmember 30. The metallurgical bonds 17 can also beformed on side surfaces of the arm portion 132 and the base 110 at theedges of the end bracket 34 of the rear crossmember 34 that also jointhe side bracket 100 to the rear crossmember 30. As such, the top andbottom base surfaces 140 can be joined to front and side edges of theupper and lower bracket arms 36 and 38 of the end bracket 34, and theend surface 138 can be joined to a side edge of the back portion 32 atthe end bracket 34.

The metallurgical bonds 18 can be formed at interfaces between the endbracket 34 of the rear crossmember 30, and top and bottom surfaces ofthe straight arm 50 where the top and bottom surfaces begin to protrudefrom the end bracket 34. These metallurgical bonds 18 can extendorthogonal to the length direction of the straight arm 50 and can becontinuous with one or more of the metallurgical bonds 17. Metallurgicalbonds 18 can also be formed at interfaces between the inside surface ofthe straight arm 50, opposite the side surface to which the side bracketis metallurgically bonded to, and internal surfaces of the end bracket34 (in particular, surfaces of the back portion 32, upper bracket arm 36and lower bracket arm 38). As such, the top and bottom surfaces of thestraight arm 50 can be joined to front edges of the upper and lowerbracket arms of the end bracket 34, and the inside surface of thestraight arm 50 can be joined to the internal surfaces of the backportion 32, the upper bracket arm 36 and the lower bracket arm 38.

FIG. 7 is a flowchart of a method 700 for manufacturing a subframeassembly for a vehicle. The method 700 includes metallurgically bondinga base 110 of a side bracket 100 to a side surface of a straight arm 50at step 702. The side bracket includes the base 110 and a rear bracketarm 130 extending from an end of the base 110 and defines a hole 136adapted to receive a screw or pin for connecting a control arm 200 of awheel suspension to the subframe assembly 10. The method also includesinserting an end of the straight arm 50 and at least a portion of therear bracket arm 130 into an end bracket 34 of a crossmember 30 at step704. The end bracket 34 is disposed at an end of the crossmember 30. Themethod further includes metallurgically bonding each of the end of thestraight arm 50 and the rear bracket arm 130 to the end bracket 34 ofthe crossmember 30 at step 706.

The method can include inserting an end of the base 110 into the endbracket 34 and metallurgically bonding the end of the base 110 to theend bracket 34 of the crossmember 30. In embodiments, a portion of therear bracket arm 130 can protrude from the end bracket 34 of thecrossmember 30, and the step of metallurgically bonding the rear bracketarm 130 to the end bracket 34 of the crossmember 30 includes formingmetallurgical bonds 17 at interfaces between the end bracket 34 of thecrossmember 30 and protruding surfaces of the rear bracket arm 130.

Further, the rear bracket arm 130 can include the arm portion 132extending from and disposed orthogonal to the base 110 and a bodyportion 134 extending from the arm portion 132 with the body portion 134extending beyond an end of the base 110, being offset from the base 110,and defining the hole 136. The step of inserting the end of the straightarm 50 and the at least the portion of the rear bracket arm 130 into theend bracket 34 of the crossmember 30 includes positioning the end of thestraight arm 50 and an end of the body portion 134 proximal to a backportion 32 of the crossmember 30.

Yet further, the step of metallurgically bonding the base 110 of theside bracket 100 to the side surface of the straight arm 50 can includelocating the side bracket 100 such that the base 110 is offset from theend of the straight arm 50. Still further, the straight arm 50 candefine a depression 52 at an upper surface thereof adjacent to the sidesurface, and the step of metallurgically bonding the base 110 of theside bracket 100 to the side surface includes locating the side bracket100 such that the side bracket 100 does not overlap with the depression52 along a length of the straight arm 50. Thus, the metallurgical bondsof the side bracket 100 are only on a single end of the straight arm 50relative to the depression 52 to prevent further stiffening of thesubframe assembly 10 at the depression 52.

As discussed above, the connection 15 as disclosed herein can form astrong and rigid connection between the rear crossmember 30, thestraight arm 50, and the side bracket 100 in the area of the control armconnection of a wheel suspension, while maintaining a long length of thestraight arm 50 that is unencumbered by rigid connections to othercomponents of the subframe assembly 10. This can preserve a desiredductility of the straight arm 50 over that length. This is at leastpartially facilitated by metallurgically bonding the side bracket 100 toa side of the straight arm 50 at an end thereof. This overallconfiguration along with the use of extruded metals for variouscomponents of the subframe assembly 10 can result in the subframe 10having the ductility needed to properly deform and absorb energy duringa crash event.

In different crash load cases, the subframe assembly 10 can receive hugeamounts of energy. FIG. 8 is a side perspective view of the subframeassembly 10 of FIG. 1 deformed from absorbing energy during a crashevent. As can be seen in FIG. 8 , during the crash event, the straightarm 50 can bend, such as at the location of the depression 52 and thesubframe assembly 10 can generally deform into a U-shape, while theconnections, such as the connection 15 stay intact due to the strengthand rigidity of the connections. Other members of the subframe assembly10 can also deform and absorb energy.

This deformation, while the connections are maintained, can result inthe subframe assembly 10 absorbing a significant amount of energy duringthe crash event, which can prevent too much energy transfer from thesubframe assembly 10 to the occupant compartment, can achieve a lowvehicle pulse index and can prevent intrusion into the occupantcompartment. Further, the deformation of the subframe assembly 10 into aU-shape can avoid stack-up with other parts of the vehicle.

Further, the connection 15 can simplify the connection to the lowercontrol arm 200. As can be seen in FIGS. 2 and 3 , the control arm bush205 can be secured to the subframe assembly 10 via the side bracket 100by a single control arm fastener 210, while other solutions requiresignificantly more components and fasteners.

Further, the strong and rigid connection 15 between the rear crossmember30, the straight arm 50, and the side bracket 100 as disclosed hereincan strengthen the subframe assembly 10 so that the subframe assembly 10is more durable under high misuse and endurance loads. Such durabilityis particularly important for heavy vehicles, such as EV vehicles.

FIG. 9 is a partial perspective view of the subframe assembly 10 at theconnection 15 between the rear crossmember 30, the straight arm 50, andthe side bracket 100, highlighting the associated weld joints 900. Thebase 110 of the side bracket 100, which is disposed abutting theoutboard side of the straight arm 50, is welded directly to the outboardside of the straight arm 50 along the top and bottom edges of the base110 and straight arm 50, as well as long the front edge of the base 110.The end bracket 34 of the rear crossmember 30 is also welded to the rearbracket arm 130 coupled to the base 110 at the top and bottom junctionsbetween the end bracket 34 and the rear bracket arm 130. Further, theend bracket 34 is welded to the to and bottom surfaces of the straightarm 50.

Referring to FIGS. 10-13 , in another exemplary embodiment, the subframeassembly 10 utilizes a side bracket 100 with a base 110 including aninboard side protrusion 1000 and a straight arm 50 with a correspondingrecess 1010, as well as conformal chamfered weld joints 1020. Asillustrated, a hollow or solid protrusion 1000 is disposed on theinboard side of the side bracket 100 extending from the base 110. Thisprotrusion 1000 may have a substantially square shape, a substantiallyrectangular shape, or any other suitable shape, optionally havingradiused corners, for example. The protrusion 1000 mates with acorresponding recess 1010 for in the outboard side of the straight arm50, thereby increasing the strength of the subframe assembly 10 in thisarea and moving the weld joints 900 (FIG. 9 ) away from high stressareas along the top and bottom edges of the base 110. The top and bottomedges of the base 110, protrusion 1000, and recess 1010 include achamfer 1030 that provides an enhanced conformal fillet weld joint 1020.Other weld joints may be as before. Advantageously, the conformalchamfered weld joint 1020 avoids potential weld cracking, with theprotrusion 1000 and conformal recess 1010 significantly reducing lodason the welds 900.

Although the present disclosure is illustrated and described herein withreference to preferred embodiments and specific examples thereof, itwill be readily apparent to those of ordinary skill in the art thatother embodiments and examples may perform similar functions and/orachieve like results. All such equivalent embodiments and examples arewithin the spirit and scope of the present disclosure, are contemplatedthereby, and are intended to be covered by the following non-limitingclaims for all purposes.

What is claimed is:
 1. A subframe assembly for a vehicle, the subframeassembly comprising: a straight arm; and a side bracket comprising abase coupled to an outboard side of the straight arm; wherein theoutboard side of the straight arm defines a recess; and wherein aninboard side of the base of the side bracket comprises a protrusion thatnests conformally within the recess defined by the outboard side of thestraight arm.
 2. The subframe assembly of claim 1, wherein top andbottom edges of the outboard side of the straight arm, the recess, theinboard side of the base of the side bracket, and the protrusion arechamfered.
 3. The subframe assembly of claim 2, wherein the chamferedportions of the top and bottom edges of the outboard side of thestraight arm, the recess, the inboard side of the base of the sidebracket, and the protrusion are welded to join the side bracket to theoutboard side of the straight arm.
 4. The subframe assembly of claim 1,wherein the protrusion is a square or rectangular protrusion havingradiused corners.
 5. The subframe assembly of claim 1, wherein theprotrusion is a hollow structure.
 6. The subframe assembly of claim 1,wherein the straight arm is an extruded structure.
 7. The subframeassembly of claim 1, wherein the side bracket is adapted to receive asuspension component of the vehicle.
 8. A side bracket for a subframeassembly for a vehicle, the side bracket comprising: a base adapted tobe coupled to an outboard side of a straight arm; wherein an inboardside of the base comprises a protrusion that is adapted to nestconformally within a recess defined by the outboard side of a straightarm.
 9. The side bracket of claim 8, wherein top and bottom edges of theinboard side of the base and the protrusion are chamfered.
 10. The sidebracket of claim 9, wherein the chamfered portions of the inboard sideof the base and the protrusion are adapted to be welded to join the sidebracket to the outboard side of the straight arm.
 11. The side bracketof claim 8, wherein the protrusion is a square or rectangular protrusionhaving radiused corners.
 12. The side bracket of claim 8, wherein theprotrusion is a hollow structure.
 13. The side bracket of claim 8, wherethe straight arm is an extruded structure.
 14. The side bracket of claim8, wherein the side bracket is adapted to receive a suspension componentof the vehicle.
 15. A straight arm for a subframe assembly for avehicle, the straight arm comprising: an extruded structure having anoutboard side adapted to be coupled to a side bracket; wherein theoutboard side of the extruded structure defines a recess; and whereinthe recess is adapted to conformally receive a protrusion of an inboardside of a base of the side bracket.
 16. The straight arm of claim 15,wherein top and bottom edges of the outboard side of the straight armand the recess are chamfered.
 17. The straight arm of claim 16, whereinthe chamfered portions of the top and bottom edges of the outboard sideof the straight arm and the recess are adapted to be welded to join theside bracket to the outboard side of the straight arm.
 18. The straightarm of claim 15, where the protrusion is a square or rectangularprotrusion having radiused corners.
 19. The straight arm of claim 15,where the protrusion is a hollow structure.
 20. The straight arm ofclaim 15, where the side bracket is adapted to receive a suspensioncomponent of the vehicle.